Hemispheric compensation in a child with left cerebral hypoplasia

Abstract

The neuropsychological examination of an adolescent female with left cerebral hypoplasia and agenesis of the left middle cerebral artery is presented. Despite the absence of a functioning left hemisphere, there was notable selective sparing of higher cortical functions, apparently due to the right hemisphere's assumption of control of functions that would otherwise be mediated by the left hemisphere. The pattern of performance suggested that two factors limited right hemispheric compensation: (a) the degree of normal bilateral representation of a function, and (b) an upper limit on the number of functions that can be mediated within a single hemisphere.